class FilterModule(object):
    def filters(self):
        return {
            'manala_bind_zone_file': self.manala_bind_zone_file,
            'walker_ip4_ptr': self.walker_ip4_ptr		
        }
 
    def manala_bind_zone_file(self, value):
        return 'db.' + value.replace('.in-addr.arpa', '')
        
    def walker_ip4_ptr(self, value):
		parts = list(reversed(value.split('.')))
		parts.append('in-addr')
		parts.append('arpa.')
		return '.'.join(parts)
        